Setting Guidelines; Current Reversal - ABB Relion REC670 Applications Manual

Section 14
Scheme communication
Strong
source
A
IEC99000054 V3 EN-US
Figure 178: Initial condition for weak-end infeed
14.5.3

Setting guidelines

The parameters for the current reversal and weak-end infeed logic for residual overcurrent
protection function are set via the local HMI or PCM600.
Common base IED values for primary current (
power (
GlobalBaseSel : It is used to select a GBASVAL function for reference of base values.
14.5.3.1

Current reversal

The current reversal function is set on or off by setting the parameter
Time delays shall be set for the timers
tPickUpRev is chosen shorter (<80%) than the breaker opening time, but minimum 20 ms.
tDelayRev is chosen at a minimum to the sum of protection reset time and the communication
reset time. A minimum
The reset time of the directional residual overcurrent protection (EF4PTOC) is typically 25 ms.
If other type of residual overcurrent protection is used in the remote line end, its reset time
should be used.
The signal propagation time is in the range 3 – 10 ms/km for most types of communication
media. In communication networks small additional time delays are added in multiplexers and
repeaters. Theses delays are less than 1 ms per process. It is often stated that the total
propagation time is less than 5 ms.
When a signal picks-up or drops out there is a decision time to be added. This decision time is
highly dependent on the interface between communication and protection used. In many
cases an external interface (teleprotection equipment) is used. This equipment makes a
decision and gives a binary signal to the protection device. In case of analog teleprotection
equipment typical decision time is in the range 10 – 30 ms. For digital teleprotection
equipment this time is in the range 2 – 10 ms.
If the teleprotection equipment is integrated in the protection IED the decision time can be
slightly reduced.
The principle time sequence of signaling at current reversal is shown.
354
SBase ) are set in a Global base values for settings function GBASVAL.
tDelayRev setting of 40 ms is recommended.
Weak
source
B
IEC99000054-3-en.vsd
IBase ), primary voltage (UBase) and primary
tPickUpRev and tDelayRev .
1MRK 511 358-UEN A
IP15042-1 v1
M13933-4 v5
M13933-6 v5
CurrRev to On or Off .
Application manual